Reinforced cylinder head gasket Toyota 2UZ-FE

The Toyota engines covered

The Toyota 2UZ-FE is a V8 with a displacement of 4.7 litres (4664 cm³) and 32 valves. It powers the Toyota Land Cruiser 100 and 200, 4Runner, Sequoia and Tundra, as well as the Lexus LX 470 and GX 470.

It takes two original cylinder head gaskets, one per cylinder bank: 11116-50040 and 11115-50050, or 11116-50070 and 11115-50080 depending on the version. Toyota publishes neither their bore, nor their thickness, nor their construction. Sized for standard combustion pressure, they lose clamping load when it rises: the head then lifts slightly and coolant finds its way into a cylinder.

Reinforced cylinder head gaskets

Sealing does not come from the gasket alone: it holds because the bolts keep the cylinder head clamped to the block. A composite gasket is crushed for good beyond 100 N/mm² of allowable stress, whereas the 301 stainless steel of the MLS gaskets withstands 517 N/mm², 5 times more, and recovers its shape after every combustion.

This page brings together the multi-layer steel MLS gaskets from Cometic, a racing gasket manufacturer. They come in 92.3 and 98 mm bores and in thicknesses from 0.69 to 3.56 mm, enough to adjust the compression ratio without touching the pistons or the cylinder head. As a general rule, choose a gasket bore at least 0.5 mm larger than the actual cylinder bore. Each part number is sold individually, and the engine takes two, one per cylinder bank.

Technical specifications

Gasket volume: the volume the gasket occupies above each cylinder. It adds to the combustion chamber; the larger it is, the lower the compression ratio. These values can only be compared between gaskets of the same bore.

Preparation and fitting

Before fitting, check the flatness of the cylinder head and the block with a straightedge, and have them resurfaced if needed. These gaskets are fitted without gasket compound: Cometic supplies them already coated.

Technical guide

The construction offered

Cometic MLS A stack of stainless steel sheets, stamped and then riveted together. The outer sheets carry active beads around every cylinder and every fluid passage. The seal is obtained under a moderate clamping load, with reduced bore distortion. It is the versatile choice, from the tuned naturally aspirated engine to mild forced induction.

Choosing bore and thickness

Gasket bore. The Cometic MLS is available in 92.3 and 98 mm. Each cylinder bank has its own part numbers: C4358 (92.3 mm) and C4212 (98 mm) for the left bank, C4357 (92.3 mm) and C4211 (98 mm) for the right bank.

Thickness. Toyota does not give the thickness of the original gasket: measure the one you remove. The thicker the gasket, the larger the combustion chamber and the lower the compression ratio; a thinner gasket has the opposite effect.

With a thickness below the original, measure the piston protrusion above the block with a dial gauge: it sets the clearance left between piston and cylinder head. The engine takes two gaskets, one per cylinder bank: order the part number for each bank.

The brand

Cometic Gasket, Inc., founded in 1989 in Concord, Ohio, is an American manufacturer of gaskets and engine sealing solutions. Its expertise is the made-to-order gasket, at the bore and thickness required. All of its production is manufactured in the United States, from American materials.

Advantages over the original gasket

When a reinforced gasket becomes necessary

• Engine being fitted with forced induction, or having its boost pressure raised
• Cylinders rebored beyond what the 92.3 and 98 mm bores of these gaskets cover
• Compression ratio to be changed, upwards or downwards
• Engine that has already blown its gasket or is using coolant
• Racing use, with repeated rises in temperature

Vehicle compatibility

OEM part numbers: 11116-50040 and 11115-50050, or 11116-50070 and 11115-50080 depending on the version.

Important: the 1UZ-FE takes different original cylinder head gaskets and is not covered by the part numbers on this page.

Why switch to a reinforced gasket?

The reinforced gasket holds out where the original one reaches its limit: under higher combustion pressure, it keeps its shape instead of being crushed.

As soon as power rises, through a turbo, a supercharger or a raised compression ratio, the head gasket becomes the weak point of the top end. A reinforced gasket is then no longer a comfort but a safeguard: it prevents the failure, and the head removal that goes with it.